I have a brand new G-RAID w/ Thunderbolt 8TB that is refusing to go to sleep (spin down) when not in use. I have 4 other external drives attached to the same system from other manufacturers. A Seagate USB, a WD FW800, etc. All the other drives spin down properly when not in use.

From the moment I added this drive, it has never slept properly. I done extensive trouble shooting of this issue all the way up to booting the machine in a completely clean state (OS X 10.8.1 only) to see if anything third party was affecting it, and the drive still refuses to spin down.

Even more strange, if I dismount any of my externals, they immediately spin down upon full OS dismount. The G-RAID w/ Thunderbolt does not. It will dismount from the OS, then continue to spin until I manually press the power button on the back.